The structure and entire sequence of the human globin genes have previously been analyzed but the function of their suspected regulatory or control regions have to be tested in mammalian cells. Using recombinant plasmids, we are attempting to introduce human Beta-globin genes into the human K562 cells. In preparation for this transfection, the vector with the selected DNA insert has been isolated and amplified in E. coli. Selected transfected K562 cells will be analyzed for the expression of the betaglobin gene and its responsiveness to inducers of hemoglobin synthesis.